Sound reproduction using more than two channels for providing an enhanced spatial experience has become very popular. For example, home cinema sound systems employing five or seven different spatial channels have become very popular. However, in order to reduce the impact of having to provide such a high number of sound sources, most home cinema sound systems use relatively small satellite loudspeakers for mid and high frequency reproduction combined with a subwoofer for low frequency reproduction. Such an arrangement exploits the fact that human perception predominantly takes the spatial direction cues from mid to high frequencies whereas the spatial cues from low frequency audio are often relatively insignificant.
The frequency that indicates the differentiation between the subwoofer's frequency range and the satellite speakers' frequency range is typically referred to as the cross-over frequency. The size and quality of the satellite drivers is a compromise between sound quality, design and cost. In particular, the desire to reduce the size of the satellite loudspeakers results in the cross-over frequency often being selected to be relatively high and may in practice often be in the range of e.g. 100-250 Hz (most typically around 150-200 Hz.
However, at these frequencies the radiated sound will be perceived to have some directional cues and the high cross-over frequency may thus reduce the perceived quality and may in particular result in degraded spatial perception. Indeed, typically the sound stage tends to become blurry, and attenuated voices may be perceived to originate partially from the subwoofer rather than the desired spatial position.
Hence, an improved system would be advantageous and in particular a system allowing increased flexibility, improved spatial perception, improved quality, reduced size speakers, facilitated implementation and/or improved performance would be advantageous.